13,141 research outputs found
Recovery heart rates as a predictor of race position in race-fit National Hunt racehorses
Prediction of race-fitness using the principles of excess post-exercise oxygen consumption is a potentially valuable applied exercise physiology tool. We hypothesised that horses with a faster heart rate recovery (HRR) after a field test would perform better in their subsequent race. Twenty mature (17 experienced, 3 unraced) National Hunt horses (15 geldings, 5 mares; 6.5±1.1 years; 489±33.5 kg), underwent 34 pre-race 3-interval field exercise tests using telemetric heart rate (HR) and global positioning satellite (GPS) monitoring on a 1,400 m track inclined 32 m. Horses were classified into 3 groups based on post-exercise HRR values obtained 1 minute after peak HR during interval 3 (>140 bpm; unfit; 120-140 bpm; fit-to-race; <120 bpm; fully fit). All horses were from the same yard, under the same management and in their final stage of training (race-ready). Horses were excluded if they were lame or clinically unwell. The outcome measure of finishing in the top third of the field was compared to classification using 2Ă2 tables (Statcalc, EpiInfo). Peak HR, peak speed and 1 min HRR were 213.4±5.1 bpm, 49.3±1.8 kph and 125.3±15.8 for interval 3. Horses classified as unfit (n=8) did not race. Fully fit and fit-to-race horses competed in 26 jump races (23 hurdles, 3 bumper; 3,200-5,000 m). Fully fit (n=16) horses were more likely to finish in the top 3 of the field than fit-to-race (n=10) (odds ratio 12.0; 95% confidence interval 1.8-81.7; P=0.01). We conclude that HRR following interval exercise can be used as a predictor of race position in National Hunt racehorses and a useful guide for trainers
Exploitation of symmetry in periodic Self-Consistent-Field ab initio calculations: application to large three-dimensional compounds
Symmetry can dramatically reduce the computational cost (running time and memory allocation) of Self-Consistent-Field ab initio calculations for crystalline systems. Crucial for running time is use of symmetry in the evaluation of one- and two-electron integrals, diagonalization of the Fock matrix at selected points in reciprocal space, reconstruction of the density matrix. As regards memory allocation, full square matrices (overlap, Fock and density) in the Atomic Orbital (AO) basis are avoided and a direct transformation from the packed AO to the SACO (Symmetry Adapted Crystalline Orbital) basis is performed, so that the largest matrix to be handled has the size of the largest sub-block in the latter basis. We here illustrate the effectiveness of this scheme, following recent advancements in the CRYSTAL code, concerning memory allocation and direct basis set transformation. Quantitative examples are given for large unit cell systems, such as zeolites (all-silica faujasite and silicalite MFI) and garnets (pyrope). It is shown that the full SCF of 3D systems containing up to 576 atoms and 11136 Atomic Orbitals in the cell can be run with a hybrid functional on a single core PC with 500 MB RAM in about 8 h. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg
A pHâSwitchable Triple HydrogenâBonding Motif
A stimuli responsive linear hydrogen bonding motif, capable of inâ
situ protonation and deprotonation, has been investigated. The interactions of the responsive hydrogen bonding motif with complementary partners were examined through a series of 1H NMR experiments, revealing that the recognition preference of the responsive hydrogen bonding motif in a mixture can be switched between two states
Genotype-by-sex-by-diet interactions for nutritional preference, dietary consumption, and lipid deposition in a field cricket
This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this recordChanges in feeding behaviour, especially the overconsumption of calories, has led to a rise in the rates of obesity, diabetes, and other associated disorders in humans and a range of animals inhabiting human-influenced environments. However, understanding the relative contribution of genes, the nutritional environment, and their interaction to dietary intake and lipid deposition in the sexes still remains a major challenge. By combining nutritional geometry with quantitative genetics, we determined the effect of genes, the nutritional environment, and their interaction on the total nutritional preference (TP), total diet eaten (TE), and lipid mass (LM) of male and female black field crickets (Teleogryllus commodus) fed one of four diet pairs (DPs) differing in the ratio of protein to carbohydrate and total nutritional content. We found abundant additive genetic variance for TP, TE, and LM in both sexes and across all four DPs, with significant genetic correlations between TE and TP and between TP and LM in males. We also found significant genotype-by-DP and genotype-by-sex-by-DP interactions for each trait and significant genotype-by-sex interactions for TE and LM. Complex interactions between genes, sex, and the nutritional environment, therefore, play an important role in nutrient regulation and lipid deposition in T. commodus. This finding may also help explain the increasing rate of obesity and the maintenance of sex differences in obesity observed across many animal species, including humans.H was funded by a University Royal Society Fellowship and Equipment Grant and by NERC (NE/G00949X/1) and AJW by a BBSRC Fellowship. JR was funded by a NERC studentship (NERC/1200242) awarded to JH
Simplicial gauge theory on spacetime
We define a discrete gauge-invariant Yang-Mills-Higgs action on spacetime
simplicial meshes. The formulation is a generalization of classical lattice
gauge theory, and we prove consistency of the action in the sense of
approximation theory. In addition, we perform numerical tests of convergence
towards exact continuum results for several choices of gauge fields in pure
gauge theory.Comment: 18 pages, 2 figure
How artificial intelligence tools can be used to assess individual patient risk in cardiovascular disease: problems with the current methods
BACKGROUND: In recent years a number of algorithms for cardiovascular risk assessment has been proposed to the medical community. These algorithms consider a number of variables and express their results as the percentage risk of developing a major fatal or non-fatal cardiovascular event in the following 10 to 20 years DISCUSSION: The author has identified three major pitfalls of these algorithms, linked to the limitation of the classical statistical approach in dealing with this kind of non linear and complex information. The pitfalls are the inability to capture the disease complexity, the inability to capture process dynamics, and the wide confidence interval of individual risk assessment. Artificial Intelligence tools can provide potential advantage in trying to overcome these limitations. The theoretical background and some application examples related to artificial neural networks and fuzzy logic have been reviewed and discussed. SUMMARY: The use of predictive algorithms to assess individual absolute risk of cardiovascular future events is currently hampered by methodological and mathematical flaws. The use of newer approaches, such as fuzzy logic and artificial neural networks, linked to artificial intelligence, seems to better address both the challenge of increasing complexity resulting from a correlation between predisposing factors, data on the occurrence of cardiovascular events, and the prediction of future events on an individual level
Strategies for Supporting Smoking Cessation Among Indigenous Fathers: A Qualitative Participatory Study
© The Author(s) 2019. There is a need for tailored smoking cessation programs specifically for Indigenous fathers who want to quit smoking.The aim of this study was to engage Indigenous men and key informants in guiding cultural adaptations to the Dads in Gear (DIG) cessation program. In Phase 1 of this qualitative participatory study, Indigenous men were engaged in group sessions and key informants in semistructured interviews to gather advice related to cultural adaptations to the DIG program. These data were used to guide the development of program prototypes. In Phase 2, the prototypes were evaluated with Indigenous fathers who were using tobacco (smoking or chewing) or were ex-users. Data were analyzed inductively. Recommendations for programming included ways to incorporate cultural values and practices to advance menâs cultural knowledge and the need for a flexible program design to enhance feasibility and acceptability among diverse Indigenous groups. Men also emphasized the importance of positive message framing, building trust by providing âhonest information,â and including activities that enabled discussions about their aspirations as fathers as well as cultural expectations of current-day Indigenous men. That the Indigenous menâs level of involvement with their children was diverse but generally less prescriptive than contemporary âinvolved fatheringâ discourse was also a key consideration in terms of program content. Strategies were afforded by these insights for meeting the men where they are in terms of their fatheringâas well as their smoking and physical activity. This research provides a model for developing evidence-based, gender-specific health promotion programs with Indigenous men
Structural optimization of reversible dibromomaleimide peptide stapling
Methods to constrain peptides in a bioactive αâhelical conformation for inhibition of proteinâprotein interactions represent an ongoing area of investigation in chemical biology. Recently, the first example of a reversible âstaplingâ methodology was described which exploits native cysteine or homocysteine residues spaced at the i and iâ+â4 positions in a peptide sequence together with the thiol selective reactivity of dibromomaleimides (a previous study). This manuscript reports on the optimization of the maleimide based constraint, focusing on the kinetics of macrocyclization and the extent to which helicity is promoted with different thiol containing amino acids. The study identified an optimal stapling combination of X1 = LâCys and X5 = LâhCys in the context of the model peptide AcâX1AAAX5âNH2, which should prove useful in implementing the dibromomaleimide stapling strategy in peptidomimetic ligand discovery programmes
Social risk, stigma and space: key concepts for understanding HIV vulnerability among black men who have sex with men in New York City
Black men who have sex with men in the USA face disproportionate incidence rates of HIV. This paper presents findings from an ethnographic study conducted in New York City that explored the structural and socio-cultural factors shaping menâs sexual relationships with the goal of furthering understandings of their HIV-related vulnerability. Methods included participant observation and in-depth interviews with 31 Black men who have sex with men (three times each) and 17 key informants. We found that HIV vulnerability is perceived as produced through structural inequalities including economic insecurity, housing instability, and stigma and discrimination. The theoretical concepts of social risk, intersectional stigma, and the social production of space are offered as lenses through which to analyse how structural inequalities shape HIV vulnerability. We found that social risk shaped HIV vulnerability by influencing menâs decisions in four domains: 1) where to find sexual partners, 2) where to engage in sexual relationships, 3) what kinds of relationships to seek, and 4) whether to carry and to use condoms. Advancing conceptualisations of social risk, we show that intersectional stigma and the social production of space are key processes through which social risk generates HIV vulnerability among Black men who have sex with men
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